Method of making viewing tubes



March 13, 1951 w, J, CAMERON 2,544,915

METHOD OF MAKING VIEWING TUBES Original Filed July 18, 1945 2 Sheets-Sheet 1 IN V EN TOR.

Tiff/fa; LIL c2272 era/z March 13, 1951 w. J. CAMERON METHOD OF MAKING VIEWING TUBES 2 Sheets-Sheet 2' Original Filed July 18, 1945 4520672757 Ml/z'amfflamero/z wmNw mEEE Patented Mar. 13, 1951 METHOD OFMAKING VIEWING TUBES William J. Cameron, Chicago, 111.

Original application July 18, 1945, .Serial No.

Divided.- and' this application October 19,1946, SerialNO. 704,385

2 Claims. .1

The present invention relates in general to viewing instruments, generally classified as scopes, and has more particular referenceto scopes for the general inspection of restricted body cavities, thepresentapplication comprising subject matter: divided from my .co-pe'nding application for United States Letter Patent, Serial No. 605,667, filed July 18, 1945, 'forInspection Device.

Instruments of thecharacter mentioned may comprise a viewing tube, which, where the scope is for the purpose of viewing body cavities, is adapted for insertion in the cavity to be inspected, and may havea lamp, carried in position to "illuminate the tissues, at the cavityinserted end of the instrument, said end'being commonly referred to as the distal end. Inspection of the illuminated tissue is, of course, accomplished by viewing the same through thetube from its distal remote or ocular end.

In instruments of the character mentioned, the view of illuminatedtissues may be appreciably. impaired by glare. due tomultiple reflection of the light. source at the distal end of the tube, upon the inner surfaces of thetube. .Such reflections, reaching the eye of the observer at the ocular end of the tube, may interfere with the image of the illuminated tissues underobservation and reduce the clarity of the .tissue image obtainable at the ocular and of the instrument. Such impairmentof the tissue image can not-be eliminated by reducing the intensity of the illumination without undesirably reducing illumination of the tissue to be inspected.

An important object of the present invention is toprovide a tubular inspection.'device in which the view of illuminated tissues is not impairedby light glare caused by ref ections of. the light source on the inner surfaces of the tube. 7

Another important. object is'to prevent glare in scope instruments by striating the inner surfaces of the viewing. tube; a further object being to elim nate glare by transversely grooving the inner surfaces of the tube to provideiglare eliminating striae; a still'further obiect beingtoform the striations by transversely grooving a strip of tube material while in fiat condition andithen forming the strip to tubular'form.

Another important object is .toprovide an inspection tube comprising a transversely striated tube-forming strip of material bent to tubular form withits opposite side edges secured. together to form the tube.

Anotherimportant object is'to-provide an inexpensive method of producing viewing tubes having non-reflecting interior. surfaces ;.1a furtherob- 2 ject being to roughen, and thus break up, the surface of a tube-forming strip, as by striating the same, to render such surface non-light reflecting, while the strip is flat, and then curve the strip to tubular form and secure its opposed edges together to form the non-reflecting viewing tube.

Theforegoing and numerous other important objects, advantages and inherent functions of the invention will become apparent as the same are understood from the following description, which, taken in connection with the accompanying drawings, discloses the details of an inspection instrument embodying the present invention.

Referring to the drawings:

Fig. 1 is a perspective view of a hob suitable for cutting glare suppressing striations in a strip of inspection tube material;

Fig. 2 is a perspective view of the strip showing striations as formed therein by operation of the hob;

Fig. 3 is a sectional view through the hob;

Fig. 4 is a sectional view through a drawing die by means of which a striated strip may be worked to tubular form;

Fig. 5 is a perspective view of the strip in tubular form and having a longitudinal slot as produced by the die;

Figs. 6 and 7, respectively, are sectional views taken substantially along the lines 6-6 and l7 in Fig. 5;

Fig. 8 is a side elevation view of a small bore tube adapted for assembly with the longitudinally slotted'tube to provide ,a viewing tube having a mounting duct for a lamp and its support stem;

Fig. 9 is a perspective view of a portion of the tube shown in Fig. 8;

Fig. 10 is a perspective view of the parts illustrated in Figs. 5-9, after the same have been assembled to form a viewing tube;

Fig. 11 is an enlarged sectional View taken through the distal end of the viewing tube shown in Fig. 10;

Fig. 12 is a perspective view of a fitting adapted for assembly at the ocular end of the viewing element shown in Fig. 10;

Fig. 13 is a sectional view through the viewing instrument; 7

Fig. 14 is an elevation view of a detachable eyepiece or viewer and its mounting clip; V

Fig. 15 is a sectional view taken substantially along the line l5-l5 in Figs. 13 and 14, showing the eyepiece and its mounting clip in mounted position on the instrument;

. Fig. 16 is an enlarged sectional view taken substantially along the line IS -i5 in Fig..l5;

Fig. 17iis a topilblan' view of .a' lampand support stem forming a lamp mounting for use with the instrument shown in Fig. 13;

Fig. 18 is an enlarged sectional view taken substantially along the line l8l8 in Fig. 17

Fig. 19 is an enlarged sectional view taken substantially along the line l9-l9 in Fig. 18;

Fig. 20 is a perspective end view of the lamp supporting stem taken substantially alongthe line 2023 in Fig. 17; and

Fig. 21 is a perspective view of the ocular end of the instrument with lamp and eyepiece mounted in operative position.

To illustrate the invention the drawings show a bronchoscope 23, the same being an instrument particularly designed for the internal inspection of throat and bronchial tube surfaces. It will be apparent, however, that the features of the present invention are not necessarily limited specifically to bronchoscopes, but may have utility and value in scope instruments generally. The instrument 23 comprises a preferably metallic viewing tube 24 having a distal end 25 adapted for insertion into a cavity to be inspected, an ocular end 26 through which the cavity surfaces to be viewed may be inspected, and a duct 27 extending in the walls of the viewing tube, between its distal and ocular ends, for the reception of a lamp 28 supported at the end of a mounting stem 29. The arrangement is such that the stem 29 may be inserted into the duct 2? at the ocular end of the viewing tube and pushed into place carrying the lamp 2.8 in order to mount the same in the tube at the distal end thereof.

The lam 28 is of minute size and is preferably mounted at and immediately within the distal end of the viewing tube in position to illuminate tissues to be inspected through the open distal end of the tube. The lamp may be energized by suitable insulated conductors 3B, which may extend through the mounting stem 29, from the lamp to the ocular end of the tube, the stern having bent portions 3!, at its lamp remote end, fitted with an attachment socket 32 for connecting the conductors 33 with an external source of lamp energizing power.

Although the lamp 28, when energized, will deliver a relatively small amount of light, it will adequately illuminate the tissues to be inspected. A certain amount of light delivered from the lamp, however, will impinge upon the inner surfaces of the viewing tube and may be reflected through the viewing tube to its ocular end, thereby interfering with and impairing the view of illuminated tissues received by an observer at the ocular end of the instrument. In order to eliminate such view impairing reflections of the light source upon the inner surfaces of the viewing tube, such inner surfaces are conditioned to render the same substantiall non-reflective by scoring or striating such surfaces with a multiplicity of striations 33 On such inner surfaces and extending preferably transversely of the viewing tube. These striations conveniently and pref erably take the form of shallow milled grooves formed in closed spaced relationship and extending around the inwardly facing surfaces of the viewingtube. Such striations break up the light reflecting qualities of the surfaces on which formed and substantially eliminate the transfer of reflected light through the tube from the distal to its ocular end, without, however, impairing the visibility of illuminated tissues viewed through the tube. On the contrary, viewing instruments, containing the reflection suppressing striations, afford sharp, bright images of viewed 4 tissues, which are not impaired nor distorted in any way by light reflection interference.

In order to construct the viewing tube having the lamp supporting duct 21, extending longitudinally of the tube in the walls thereof, the same may be made up from a strip of preferably metallic tube material 34 and a preferably metallic duct forming tube of small bore 35. The striations 33 may be formed in the strip 34 while the same is in flat condition, as by passing the same laterally with respect to a milling cutter 36, the same comprising a plurality of thin saw discs 31 suitably clamped upon a shaft or axle 38. The saw discs 31 may be maintained in a desired spaced relation on the shaft as by means of spacing discs 39, to thereby determine the spacement of the grooves 33. After the grooves have been cut, the flat milled strip 34 may be drawn through a suitable forming die 40 to thereby bend the strip to tubular form, as shown more particularly in. Fig. 5 of the drawings, the so formed tube having a slot 4| extending longitudinally from end to end thereof. This slot is defined by the spaced apart opposite side edges of the strip 34. The tube may be beveled at its distal end and provided with a beaded edge 42, said beaded edge preferably closing the slot 4| at the distal end of the tube. It will be seen that the striations 33 form shallow spaced annular grooves upon the inner surfaces of the tubular member 34, such shallow grooves extending at least at and adjacent the distal end of the tube and preferably throughout the inner surfaces of the tube from the distal to the ocular end thereof.

The small bore tube 35 may then be assembled in the slot 41 and welded, brazed or otherwise secured in said slot, the spaced apart edges of the strip 34 being thus secured to the tube 35 in integral fashion along opposite sides thereof, thereby strengthening and rigidifying the viewing tube structure. The surfaces of the tube 35 presented inwardly of the slot 4| are also preferably provided with striations 33a which may be formed in the tube prior to its assembly in the slot, by applying the tube surfaces to the cutter 36 in order to striate the inwardly facing surfaces of the tube 35, preferably through its entire length and at least at and adjacent the distal end thereof. At the distal end of the instrument, the inwardly facingportions of the tube 35 may be cut away, as at 43, to expose the lamp 28, when in mounted position, at the .distal end of the tube.

In order to provide convenient means for manipulating the instrument, the ocular end 26 of the viewing tube 24, including its duct forming tube portions 35, is mounted in a support fitting 44 comprising a cylindrical collar 45 in which the end portions of the viewing tube are mounted and secured in any suitable fashion, as by welding or brazing. Outwardly of the end of the viewing tube, the fitting 44 i provided with arcuate slots 46 extending transversely of the fitting and opening through a common gate 41' at the end of the fitting. These arcuate slots 46 afiord convenient means for latching the lamp mounting stem in operative position in the instrument. To this end, the bent portions 3| of the stem preferably extend substantially at right angles with respect to the lamp supporting portions thereof. Said lamp supporting portions thus may be inserted, through the collar 45, into the duct 2'! at the ocular end of the instrument and may be advanced into position to present the lamp 28 in th cut out portions 43 at the i di's'tal'"end of the viewing"tube: Inorder'to'reach' such position"; the-bent portion 31: or thelamp support may enter the slots '45 throug-li the gate opening 41, the-surfaces of 'the collar45 defining one-side of said slots,- serving'to'engage'the oil'- setportions 3'! of the'lampsupport and' limit its inserting movement'in'the ductZT-WIien-the lamp 28 has reached its operative position at the distal end of the instrument. The lamp-mount may thenbe latchedinassembled position by turning'-the bent portion=3i through substantially 90 degrees, to latchit in i one or='otli'er of -"the latch; ing slots ifif The lamp and its mounting stem, oicourse; may b'e removed 'from --operative posi tion ir'rthe instrument b'y'reversing the mount'- ing'and latchingprocedure. If'desired, the socket 3'2maygbearranged in axial alignment with the bent'portion 31, or; as shown more particularly in Fig; of' thedrawings; the same may-be offsetwithrespect'to"the bent stem latching portion 3| in order that, when in latched position, the socket 32 mayextend ina'convenient, out-ofthe-wayl position, withrits: axislyingrinthe plane including the axis of the support stemzn: and the bent portion. 31, or inrposition:substantially normal to said plane as shown, thereby facilitatingmanipulation of the-instrument by locating the socket 32- in position nested with the fitting:

The-collard 5 is provided witha stem 48-, which preferably extends radially ofthe viewing tube and the duct formingtube 21;- The fitting 44% may form-a shoulder la at-"the collar connected end of the stem 48: Spacedifrom said shoulder the stem preferably carries a press fitted pin 55 extending diametrally, thereth'rough, saidlpin. 55 preferably extending in a"dir'ection parallel to the axis of the viewing tube. The end of the pin which extends toward the distal end of the instrument may be threaded for the reception of a clamp nut 5|. The stem 48 provides a mounting for a detachable handle 52, which may be of any convenient or preferred shape. This handle has a socket 53 for the reception of the stem 48, and is provided with a diametral slot 54, at the open end of the socket 53, for the reception of the pin 50 therein on opposite sides of the socket. After the handle has been mounted on the stem 48 it may be clampingly secured in place, as by tightening the clamping nut 5!.

The pin receiving portions of the handle are preferably formed to provide a clip seat 55, from which seat the end of the pin 56 remote from the clamp nut projects when the handle is in mounted position on the stem 48. The seat 55 and projecting end of the pin 58 afiord a mount ingfor a detachable eyepiece viewing device 55, said device preferably comprising an adjustable telescope viewer provided with mounting clip means 51 comprising a resilient spring clip 58 having arms adapted to clippingly engage the clip seat 55, on opposite sides of the pin 55, and portions adapted to snugly receive the projecting end of the pin 50, therebetween, whereby, when mounted, the clip will be oriented on the fitting 44 in position to support the eyepiece 55 in viewing alignment with the viewing tube at its ocular end. The mounting clip means 51, also, preferably comprises pivot means 59 whereby the eyepiece 55 may be swung on the mounting clip 58 to an offset position allowing direct ocular inspection through the viewing tube. To this end, the pivot means 58 may comprise'a cylindrical block 65 secured, as by fastening screws iii, to the clip 58 and having an axial bearing channel 62"161' turnably receiving at pivot stem' -632 The stem Ei'B -at one =end 'carrie's a;bracket 6 on which the'eyepiece orviewe1 56 is m'ounted; said bracket having a portion overlying orreend' of the block 6 0 and provided' with -aprojection 65 adapted to lit in corresponding: socket t'fi formedin the end of the'block '5 5 when' the eyepiece is'in viewingalignment with the viewing, tube-"24f- Theprojection B5'-may-engage-in' a= socket 6-1-w-hen in oil-set position. The block-- in* its end; op posite from=-thebracket 64; may be-provided with a= cavity=58'-for receiving the bracket remote end of the stem 53-; the stem-being retained in" the block Eili asby means of a fastening scr'ew 69 havinga'stem "threaded into the end of 'thestem 63and-ahead fitting'in the open end-of the cavity 68? A resilient spring lll'may'beinterposed between the'head of the fastening screw 59 and the bottom of the cavity. 58 in order to yieldingly; draw down the stem in the" channel 62*and the bracket iifl uponthe end of the block 66 to yildin'gly hold the -pin'55 in onev or other of the socketsiifiand 61.

The 1amp"supportingstem 29 maycomprise a small bore; preferably metal," tube 1l fitted withai thin tubular layerof insulating material 12': Within this layer; atthelamp supporting end' of the stem, may be .press-fittinglyfmounted a cylindrical metal sleeve" block: 13" having a threaded central bore" 14 for""threading"' engagement" with the correspondingly threaded base 15 of the lamp '28", said threaded" basetformingpa lamp terminal contact which forms electrical connection with the sleeve 1e? The'lampj base 15 also' comprises anaxially disposed terminal 16% which is disposed within-the sleeve when the lamp is in mounted" position. The conductors 3 0-'-m-a-yextend "within the-tube *1 i from the connecting socket 32 to the sleeve 13, the ends of said conductors being supported in an insulating block 11 adapted for attachment to the sleeve 13, as by threaded engagement therewith, said block having a central opening 18 therein for pressfittingly receiving one of the conductors and presenting the bared end thereof in position for engagement with the axial lamp terminal 16. The block 11 also has an opening 19 therein press-fittingly receiving the other conductor and presenting the bared end thereof for electrical connection with the sleeve 13, whereby an energizing circuit for the lamp may be provided within the tube 1!. If desired, the tube 1| may be filled with a suitable insulating compound around the conductors 36 after the same and the lamp mounting sleeve 13 have been assembled. In any event, the conductors 30 are of relatively fine gauge wire and are preferably insulated, at least by one or more coatings of shellac or other suitable insulation sufiicient to relatively insulate the conductors the one from the other within the tube 1|. The insulation, however, need be suilicient only to insulate against the relatively low voltage required for the operation of the lamp 28.

aflords the advantage of a readily attachable eyepiece viewer, which may be mounted in aligned position, or as readily detached, and which may be swung to an oifset position without detaching the same. The lamp and its support may be quickly and easily mounted in or removed from the instrument and may be latched in mounted position with a minimum of effort. The within described method of eliminating glare and, hence, of enhancing the view obtainable of tissues under observation, has the advantage that the instrument may be boiled or sterilized with steam without disturbing or impairingthe glare eliminating striations since the same comprise the actual material of the viewing tube, glare elimination being accomplished without employing any film or coating of material apt to deteriorate in the presence of sterilizing liquids or vapors.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the form herein disclosed being a preferred embodiment for the purpose of illustrating the invention; no claim being herein made to the viewing instrument per se since the same forms the subject matter claimed in my aforesaid co-pending application Serial No. 605,667.

The invention is hereby claimed as follows:

1. The method of making a viewing tube having non-reflecting internal surfaces, which comprises roughening the surface of a strip of tubeforming material, while fiat, similarly roughening the outer surface of a pre-formed pipe element, in a zone longitudinally thereof, and then bending the strip to tubular form and securing the opposed lateral edges thereof upon and along said pipe element on opposite sides of the roughened zone thereof to form a viewing tube having reflection suppressing, inwardly facing surfaces, comprising the roughened surfaces of said strip and of said pipe element.

2. The method of making a viewing tube having non-reflecting internal surfaces, which comprises forming fine, hair-like grooves in a strip of material while fiat, and then bending the strip to tubular form and securing the opposed lateral edges of the strip to and along the opposite sides of a duct pipe to rigidify the structure and to form a viewing tube having reflection suppressing grooves distributed substantially uniformly on its inwardly facing surfaces.

WILLIAM J. CAMERON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

